Lever operated hand tool improvement

ABSTRACT

An adjustable lever arm extension for use on hand tools that employ an operating lever to apply force in operation of the tool. The extension is pivoted near the extremity of the operating lever, and has a grip that releases under predetermined force to permit the extension to pivot freely after that force has been reached. This limits the maximum amount of operating force applied by the tool.

States Patent [151 3,648,540

King Mar. 14, 1972 [54] LEVER OPERATED HAND TOOL 1,099,079 6/1914IMPROVEMENT 1,733,642 10/ 1,881,060 10/1932 [72] Inventor: Robert G.Klng, Stroud, Okla. 2 31 3 4/ 959 [73] Assignee: Texaco Inn, New York,NY. 3'060'763 10/1962 Filedi 1969 Primary Examiner-William F. ODeaAssistant ExaminerF. D. Shoemaker [2U Appl' Attorney-Thomas H. Whaleyand Carl G. Ries [52] US. Cl ..74/524, 74/525, 74/544, [57] ABSTRACT 51Int. Cl. s 5 :50?) adjusable have hand um 58 Field ofSearch ..74/523 519522 584 524 emPlY 1" apply PPemim the 74,525 254/l29 81752 tool. Theextension IS pivoted near the extremlty of the operating lever, and hasa grip that releases under predetermined force to permit the extensionto pivot freely after that force [56] References cued has been reached.This limits the maximum amount of operat- UNITED STATES PATENTS s forcepp y the tool- 2,594,89l /l 952 Embree ..74/524 2 Claims, 2 DrawingFigures LEVER OPERATED HAND TOOL IMPROVEMENT BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to hand toolsgenerally and more particularly concerns an improvement for leveroperated hand tools.

2. Description of the Prior Art While there are known arrangements forindicating torque in connection with hand tools having lever armoperation, they are not known to provide a release of actuation forcewhen a predetermined maximum is reached. Nor is it known to provide anextension that is adjustable in lever arm length from the tool fulcrumwith an arrangement for releasing the application of torque to the toolwhen a predetermined amount of force has been reached. It is the latterattributes which this invention specifically provide and which makepractical a predetermined constant maximum application of torque, withrespect to hand operated tools generally.

SUMMARY OF THE INVENTION The invention relates to a combination that isapplicable to a hand tool of the type having an operating lever forapplying force in operation of the tool. The combination comprises leverextension means carried by said operating lever, and means for holdingsaid extension means in operative relation with said operating lever.The latter means comprises means for releasing said holding means when apredetermined amount of force is applied to said lever.

Also briefly, the invention concerns a hand tool of the type having anoperating lever for applying force in operation of the tool. Itcomprises in combination, a handle for use in applying said operatingforce, and means for effectively releasing said handle from operativerelationship with said tool when a predetermined maximum force isapplied.

Again briefly, the invention concerns a hand tool of the type having anoperating lever for applying force in operation of the tool. Theinvention concerns a combination which comprises an auxiliary lever armthat has a permanent magnet adjustably mounted near the inner end ofsaid auxiliary arm, and a handle located near the extremity of saidauxiliary arm. The combination also comprises a support collar forholding said auxiliary lever arm slidable longitudinally therein andpivot means for attaching said collar to said operating lever near theextremity thereof. The combination also comprises means for adjustablysecuring said auxiliary lever arm in said support collar, to permitvariable setting of the spacing of said permanent magnet from said pivotalong said operating lever.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects andbenefits of the invention will be more fully set forth below inconnection with the best mode contemplated by the inventor of carryingout the invention and in connection withwhich there are illustrationsprovided in the drawings, wherein:

FIG. I is an elevation of an assembly, illustrating the invention asapplied to the operating lever arm of a banding tool that is shown indashed lines; and

FIG. 2 is a fragmentary elevation showing the same as sembly view asFIG. 1 but with the parts in operating position for application oftorque to the operating lever of the tool.

DESCRIPTION OF THE PREFERRED EMBODIMENT It is to be observed that theinvention is applicable generally to any hand operated tool which isactuated by the application of torque, e.g., by means of an operatinglever. While FIG. I of the drawings illustrates somewhat schematically abanding tool, it will be appreciated that many other hand operated toolsmight have this invention applied thereto.

With reference to the FIGS. I and 2 of the drawings, it will be notedthat there is a hand operated tool 11 that is shown only in FIG. 1.Since it is not a material part of the invention, it is illustrated indashed lines.

Thus, there is a tool II which might take other forms but is illustratedas a banding tool. It has an operating lever 12 which is actuatedmanually to apply torque in providing operating force for actuating thetool Ill. The lever I2 is pivoted about a pivot point (FIG. I) on thetool 11, and such pivotal action applies a torque to cause operation ofthe tool.

In order to have predetermined and adjustable maximum force that may beapplied to the lever I2, there is an auxiliary lever arm 16. This andits related elements are shown somewhat exaggerated in relative sizeviz-a-viz the tool 11 and its handle or lever 12. However, it will beunderstood that such is a matter of design and therefore is a matterthat is within the purview of one skilled in the art. I

The arm 16 is slidable longitudinally within a collar I7, which in itsturn is pivotally mounted near the end of the lever 12 by means of apivot pin 20. The pin 20 extends through both sides of a bifurcatedportion of the collar 17, which portion straddles the lever arm 12. Itwill be noted that there is a set screw 2I in the top (as viewed in thedrawings) of the collar I7. This acts of fix the slidable position ofthe auxiliary lever arm 16 relative to the collar 17.

At the outer extremity (relative to the tool II) of the auxiliary arm 16there is a spherical handle 22 for being gripped manually as force isapplied to the tool. At the other end of the arm I6, i.e., the end whichwhen pivoted will lie substantially parallel with the lever arm 12 (seeFIG. 2) there is a bracket 26 that is integrally attached to the end ofthe arm 16. While the bracket 26 might take various forms, it may beconstructed of an angle shaped body which stands with one half at rightangles to the end of the arm I6 where it is attached thereto. The otherhalf lies parallel to the arm I6 so as to form a support for a permanentmagnet 27. Magnet 27 is mounted in a housing 28 in any feasible manner,e.g., by being pinned therein as indicated by a pin 29. The housing 28is mounted pivotally near the extremity of the bracket 26, and this maybe accomplished in any feasible manner such as that illustrated. Thereis provided a lug 32 which is integral with and extends from the top ofthe housing 28, and a pivot pin 33 extends through the free end of thebracket 26 and through the lug 32 so as to provide the desired pivotalsupport for the housing and the magnet contained therein.

In order to hold the pivotal support for the magnet in position toprovide an even gripping action against the lever arm I2 of the tool,there is an adjustment screw 36. The screw 36 extends througha tappedhole in the upstanding portion of bracket 26 and rests against the sideof the housing 28. There is a nut 37 which may be tightened against thebracket 26 so as to maintain a desired pivotal position of the housing28.

OPERATION It will be appreciated that the operation of this inventioninvolves the ability to adjust the maximum amount of force that will beapplied by a hand tool which employs a lever arm that is manuallyactuated. This entails the use of the pivotally attached auxiliary armI6 which is mounted near the free end of the lever 12. The arm 16 mayswing freely about its pivot 20 except when the magnet 27 is in contactwith the lever I2. It will be appreciated that if the lever 12 is notconstructed of a ferrous metal, there would be provided a strip (notshown) along the upper edge of the lever for having the magnet 27 makegripping contact therewith.

With reference to FIG. 2, it will be noted that this is the position theparts will take prior to the application of force in operation of thetool. Now, the maximum amount of force which may be applied to the tooldepends upon the total amount of force, which includes the leverage fromhandle 22 to the tool operating pivot I5. However, this is only true solong as the magnet 27 remains in gripping contact with the lever I2.Consequently, whenever the amount of force being applied to the handle22 exceeds that amount required to cause the magnet 27 to break freefrom the tool lever arm I2, the auxiliary arm I6 will pivot freely andapplication of force to the tool with cease. Thus, a predeterminedmaximum application of torque is transmitted to the tool, and this rriaybe adprising justed for different desired forces by adjusting theposition of an auxiliary lever arm with arm 16 in its supporting collar17. It will be appreciated that a permanent magnet adjustably mountednear the inner the force on the magnet 27 tending to break it out ofcontact end of said auxiliary arm, and with the lever 12, changes as thesetting of the auxiliary m 5 a handle located near the outer extremityof said auxiliary 16 is changed. arm,

As an example of the foregoing it will be noted th t if th a supportcollar for holding said auxiliary lever arm slidable auxiliary arm 16 isset with the handle 22 close to the end of longitudinally ther the leverarm 12, there will be greater force necessary to break l)wot meansattaching Said collar to Said Operating level the magnet 27 free andgreater maximum force may be apthe end thereof, f plied to the tool. Thechange (reduction) in the leverage of the meafls adlustably Securing fylever tool input will have less effect than the change in the max- $aldPP? collar to Perm1t Varlable Setting f the p imum force that can beapplied before the magnet breaks free. "8 of S ald penflanem magnet fromSaid P means While the foregoing specific embodiment of the inventionalong 531d operatmg l5 2. The invention according to claim 1 whereinsaid operating lever is constructed of ferrous metal, and

wherein said adjustable mounting for said permanent magnet is pivotal topermit even contact by the magnet with said operating lever. 4: a:

has been set forth in considerable detail in accordance with theapplicable statutes, this is not to be taken as in any way limiting theinvention but merely as being descriptive thereof.

lclaim: 1. In a hand tool of the type having an operating lever forapplying force in operation of the tool, the combination com-

1. In a hand tool of the type having an operating lever for applyingforce in operation of the tool, the combination comprising an auxiliarylever arm with a permanent magnet adjustably mounted near the inner endof said auxiliary arm, and a handle located near the outer extremity ofsaid auxiliary arm, a support collar for holding said auxiliary leverarm slidable longitudinally therein, pivot means for attaching saidcollar to said operating lever near the free end thereof, and means foradjustably securing said auxiliary lever arm in said support collar topermit variable setting of the spacing of said permanent magnet fromsaid pivot means along said operating lever.
 2. The invention accordingto claim 1 wherein said operating lever is constructed of ferrous metal,and wherein said adjustable mounting for said permanent magnet ispivotal to permit even contact by the magnet with said operating lever.